Predicting 6-month mortality risk of patients commencing dialysis treatment for end-stage kidney disease

Predicting mortality after start of long-term dialysis-International validation of one- and two-year prediction models

BACKGROUND

Mortality prediction is critical on long-term kidney replacement therapy (KRT), both for individual treatment decisions and resource planning. Many mortality prediction models already exist, but as a major shortcoming most of them have only been validated internally. This leaves reliability and usefulness of these models in other KRT populations, especially foreign, unknown. Previously two models were constructed for one- and two-year mortality prediction of Finnish patients starting long-term dialysis. These models are here internationally validated in KRT populations of the Dutch NECOSAD Study and the UK Renal Registry (UKRR).

METHODS

We validated the models externally on 2051 NECOSAD patients and on two UKRR patient cohorts (5328 and 45493 patients). We performed multiple imputation for missing data, used c-statistic (AUC) to assess discrimination, and evaluated calibration by plotting average estimated probability of death against observed risk of death.

RESULTS

Both prediction models performed well in the NECOSAD population (AUC 0.79 for the one-year model and 0.78 for the two-year model). In the UKRR populations, performance was slightly weaker (AUCs: 0.73 and 0.74). These are to be compared to the earlier external validation in a Finnish cohort (AUCs: 0.77 and 0.74). In all tested populations, our models performed better for PD than HD patients. Level of death risk (i.e., calibration) was well estimated by the one-year model in all cohorts but was somewhat overestimated by the two-year model.

CONCLUSIONS

Our prediction models showed good performance not only in the Finnish but in foreign KRT populations as well. Compared to the other existing models, the current models have equal or better performance and fewer variables, thus increasing models' usability. The models are easily accessible on the web. These results encourage implementing the models into clinical decision-making widely among European KRT populations.

Age, Gender and Diabetes as Risk Factors for Early Mortality in Dialysis Patients: A Systematic Review

Objective: To study the impact of age, gender, and presence of diabetes (any type) on the risk of early deaths (180-day mortality) in patients starting long-term hemodialysis (HD) therapy.Design: Systematic review of the literature.Setting: Out-patient (non-hospitalized), community-based HD therapy world-wide.Participants: Patients with advanced chronic kidney disease (CKD) starting long-term HD treatment for end-stage renal disease (ESRD).Methods: Medline and EMBASE were searched for studies published between 1/1/1985 and 12/31/2017. Observational studies involving adult subjects commencing HD were included. Data extracted included population characteristics and settings. In addition, patient or treatment related factors studied with reference to their relationship with the risk of early mortality were documented. The Quality in Prognosis Studies tool was used to assess risk of bias in individual studies. Findings were summarized, and a narrative account was drawn.Results: Included were 26 studies (combined population 1,098,769; representing 287,085 person-years of observation for early mortality). There were 17 cohort and 9 case-control studies. Risk of bias was low in 13 and high in a further 13 studies. Patients who died in the early period were older than those who survived. Mortality rates increased with advancing age. Female gender was associated with slightly increased early mortality rates in larger and higher quality studies. The available data showed conflicting results in relation to the association of diabetes and risk of early mortality.Conclusions: This systematic review evaluated the impact of key demographic and co-morbid factors on risk of early mortality in patients starting maintenance HD. The information could help in delivering more tailored prognostic information and planning of future interventions.

[Treatment of geriatric patients with end-stage renal failure : Dialysis or conservative procedure?]

Compared to younger patients, an acceptable state of health in older patients with various comorbidities is rarely achieved by the initiation of dialysis. Despite dialysis treatment, further functional and cognitive impairments often rapidly occur in geriatric patients. Thus, newer studies are concerned with the quality of life of this patient group after initiation of dialysis as well as with palliative treatment strategies as alternatives. A structured clarification for the patients on all possibilities with mediation of all necessary information is a prerequisite for a shared decision-making. To assess life expectancy after dialysis initiation, various scores have been developed but the sensitivity could not fulfil the expectations. In the case of renal replacement, chronic intermittent hemodialysis is the treatment form most frequently performed in geriatric patients. The main concern of conservative palliative treatment is the quality of life and the management of uremic symptoms, which have to be addressed by a multidisciplinary team.

Implication of Trends in Timing of Dialysis Initiation for Incidence of End-stage Kidney Disease

IMPORTANCE

In the last 2 decades, there have been notable changes in the level of estimated glomerular filtration rate (eGFR) at which patients initiate long-term dialysis in the US and around the world. How changes over time in the likelihood of dialysis initiation at any given eGFR level in at-risk patients are associated with the population burden of end-stage kidney disease (ESKD) has not been not well defined.

OBJECTIVE

To examine temporal trends in long-term dialysis initiation by level of eGFR and to quantify how these patterns are associated with the number of patients with ESKD.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study analyzing data obtained from a large, integrated health care delivery system in Northern California from 2001 to 2018 in successive 3-year intervals. Included individuals, ranging in number from as few as 983 122 (2001-2003) to as many as 1 844 317 (2016-2018), were adult members with 1 or more outpatient serum creatinine levels determined in the prior year.

MAIN OUTCOMES AND MEASURES

One-year risk of initiating long-term dialysis stratified by eGFR levels. Multivariable logistic regression was performed to assess temporal trends in each 3-year cohort with adjustment for age, sex, race, and diabetes status. The potential change in dialysis initiation in the final cohort (2016-2018) was estimated using the relative difference between the standardized risks in the initial cohort (2001-2003) and the final cohort.

RESULTS

In the initial 3-year cohort, the mean (SD) age was 55.4 (16.3) years, 55.0% were women, and the prevalence of diabetes was 14.9%. These characteristics, as well as the distribution of index eGFR, were stable across the study period. The likelihood of receiving dialysis at eGFR levels of 10 to 24 mL/min/1.73 m2 generally increased over time. For example, the 1-year odds of initiating dialysis increased for every 3-year interval by 5.2% (adjusted odds ratio, 1.052; 95% CI, 1.004-1.102) among adults with an index eGFR of 20 to 24 mL/min/1.73 m2, by 6.6% (adjusted odds ratio, 1.066; 95% CI, 1.007-1.130) among adults with an eGFR of 16 to 17 mL/min/1.73 m2, and by 5.3% (adjusted odds ratio, 1.053; 95% CI, 1.008-1.100) among adults with an eGFR of 10 to 13 mL/min/1.73 m2, adjusting for age, sex, race, and diabetes. The incidence of new cases of ESKD was estimated to have potentially been 16% (95% CI, 13%-18%) lower if there were no changes in system-level practice patterns or other factors besides timing of initiating long-term dialysis from the initial 3-year interval (2001-2003) to the final interval (2016-2018) assessed in this study.

CONCLUSIONS AND RELEVANCE

The present results underscore the importance the timing of initiating long-term dialysis has on the size of the population of individuals with ESKD.

Discussions during shared decision-making in older adults with advanced renal disease: a scoping review

OBJECTIVES

This review summarises the information available for clinicians counselling older patients with kidney failure about treatment options, focusing on prognosis, quality of life, the lived experiences of treatment and the information needs of older adults.

DESIGN

We followed the Joanna Briggs Institute Methodology for Scoping Reviews. The final report conforms to the PRISMA-ScR guidelines.

DATA SOURCES

PubMed, PsycINFO, CINAHL, Embase, Scopus, Web of Science, TRIP and online repositories (for dissertations, guidelines and recommendations from national renal associations).

ELIGIBILITY CRITERIA FOR INCLUSION

Articles in English studying older adults with advanced kidney disease (estimated glomerular filtration rate <30 mL/min/1.73 m²); published between January 2000 and August 2018. Articles not addressing older patients separately or those comparing between dialysis modalities were excluded.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers screened articles for inclusion and grouped them by topic as per the objectives above. Quantitative data were presented as tables and charts; qualitative themes were identified and described.

RESULTS

248 articles were included after screening 15 445 initial results. We summarised prognostic scores and compared dialysis and non-dialytic care. We highlighted potentially modifiable factors affecting quality of life. From reports of the lived experiences, we documented the effects of symptoms, of ageing, the feelings of disempowerment and the need for adaptation. Exploration of information needs suggested that patients want to participate in decision-making and need information, in simple terms, about survival and non-survival outcomes.

CONCLUSION

When discussing treatment options, validated prognostic scores are useful. Older patients with multiple comorbidities do not do well with dialysis. The modifiable factors contributing to the low quality of life in this cohort deserve attention. Older patients suffer a high symptom burden and functional deterioration; they have to cope with significant life changes and feelings of disempowerment. They desire greater involvement and more information about illness, symptoms and what to expect with treatment.

Medical Record Documentation of Goals-of-Care Discussions Among Older Veterans With Incident Kidney Failure

RATIONALE & OBJECTIVE

Elicitation and documentation of patient preferences is at the core of shared decision making and is particularly important among patients with high anticipated mortality. The extent to which older patients with incident kidney failure undertake such discussions with their providers is unknown and its characterization was the focus of this study.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

A random sample of veterans 67 years and older with incident kidney failure receiving care from the US Veterans Health Administration between 2005 and 2010.

EXPOSURES

Demographic and facility characteristics, as well as predicted 6-month mortality risk after dialysis initiation and documentation of resuscitation preferences.

OUTCOMES

Documented discussions of dialysis treatment and supportive care.

ANALYTICAL APPROACH

We reviewed medical records over the 2 years before incident kidney failure and up to 1 year afterward to ascertain the frequency and timing of documented discussions about dialysis treatment, supportive care, and resuscitation. Logistic regression was used to identify factors associated with these documented discussions.

RESULTS

The cohort of 821 veterans had a mean age of 80.9±7.2 years, and 37.2% had a predicted 6-month mortality risk>20% with dialysis. Documented discussions addressing dialysis treatment and resuscitation were present in 55.6% and 77.1% of patients, respectively. Those addressing supportive care were present in 32.4%. The frequency of documentation varied by mortality risk and whether the patient ultimately started dialysis. In adjusted analyses, the frequency and pattern of documentation were more strongly associated with geographic location and receipt of outpatient nephrology care than with patient demographic or clinical characteristics.

LIMITATIONS

Documentation may not fully reflect the quality and content of discussions, and generalizability to nonveteran patients is limited.

CONCLUSIONS

Among older veterans with incident kidney failure, discussions of dialysis treatment are decoupled from other aspects of advance care planning and are suboptimally documented, even among patients at high risk for mortality.

Prediction of Risk of Death for Patients Starting Dialysis: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

Dialysis is a preference-sensitive decision where prognosis may play an important role. Although patients desire risk prediction, nephrologists are wary of sharing this information. We reviewed the performance of prognostic indices for patients starting dialysis to facilitate bedside translation.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Systematic review and meta-analysis following the PRISMA guidelines. We searched Ovid MEDLINE, Ovid Embase, Ovid Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus for eligible studies of patients starting dialysis published from inception to December 31, 2018.

SELECTION CRITERIA

Articles describing validated prognostic indices predicting mortality at the start of dialysis. We excluded studies limited to prevalent dialysis patients, AKI and studies excluding mortality in the first 1-3 months. Two reviewers independently screened abstracts, performed full text assessment of inclusion criteria and extracted: study design, setting, population demographics, index performance and risk of bias. Pre-planned random effects meta-analysis was performed stratified by index and predictive window to reduce heterogeneity.

RESULTS

Of 12,132 articles screened and 214 reviewed in full text, 36 studies were included describing 32 prognostic indices. Predictive windows ranged from 3 months to 10 years, cohort sizes from 46 to 52,796. Meta-analysis showed discrimination area under the curve (AUC) of 0.71 (95% confidence interval, 0.69 to 073) with high heterogeneity (I2=99.12). Meta-analysis by index showed highest AUC for The Obi, Ivory, and Charlson comorbidity index (CCI)=0.74, also CCI was the most commonly used (ten studies). Other commonly used indices were Kahn-Wright index (eight studies, AUC 0.68), Hemmelgarn modification of the CCI (six studies, AUC 0.66) and REIN index (five studies, AUC 0.69). Of the indices, ten have been validated externally, 16 internally and nine were pre-existing validated indices. Limitations include heterogeneity and exclusion of large cohort studies in prevalent patients.

CONCLUSIONS

Several well validated indices with good discrimination are available for predicting survival at dialysis start.

Machine Learning to Identify Dialysis Patients at High Death Risk

Introduction

Given the high mortality rate within the first year of dialysis initiation, an accurate estimation of postdialysis mortality could help patients and clinicians in decision making about initiation of dialysis. We aimed to use machine learning (ML) by incorporating complex information from electronic health records to predict patients at risk for postdialysis short-term mortality.

Methods

This study was carried out on a contemporary cohort of 27,615 US veterans with incident end-stage renal disease (ESRD). We implemented a random forest method on 49 variables obtained before dialysis transition to predict outcomes of 30-, 90-, 180-, and 365-day all-cause mortality after dialysis initiation.

Results

The mean (±SD) age of our cohort was 68.7 ± 11.2 years, 98.1% of patients were men, 29.4% were African American, and 71.4% were diabetic. The final random forest model provided C-statistics (95% confidence intervals) of 0.7185 (0.6994–0.7377), 0.7446 (0.7346–0.7546), 0.7504 (0.7425–0.7583), and 0.7488 (0.7421–0.7554) for predicting risk of death within the 4 different time windows. The models showed good internal validity and replicated well in patients with various demographic and clinical characteristics and provided similar or better performance compared with other ML algorithms. Results may not be generalizable to non-veterans. Use of predictors available in electronic medical records has limited the assessment of number of predictors.

Conclusion

We implemented and ML-based method to accurately predict short-term postdialysis mortality in patients with incident ESRD. Our models could aid patients and clinicians in better decision making about the best course of action in patients approaching ESRD.

Where Are You Going, Nephrology? Considerations on Models of Care in an Evolving Discipline

Nephrology is a complex discipline, including care of kidney disease, dialysis, and transplantation. While in Europe, about 1:10 individuals is affected by chronic kidney disease (CKD), 1:1000 lives thanks to dialysis or transplantation, whose costs are as high as 2% of all the health care budget. Nephrology has important links with surgery, bioethics, cardiovascular and internal medicine, and is, not surprisingly, in a delicate balance between specialization and comprehensiveness, development and consolidation, cost constraints, and competition with internal medicine and other specialties. This paper proposes an interpretation of the different systems of nephrology care summarising the present choices into three not mutually exclusive main models (“scientific”, “pragmatic”, “holistic”, or “comprehensive”), and hypothesizing an “ideal-utopic” prevention-based fourth one. The so-called scientific model is built around kidney transplantation and care of glomerulonephritis and immunologic diseases, which probably pose the most important challenges in our discipline, but do not mirror the most common clinical problems. Conversely, the pragmatic one is built around dialysis (the most expensive and frequent mode of renal replacement therapy) and pre-dialysis treatment, focusing attention on the most common diseases, the holistic, or comprehensive, model comprehends both, and is integrated by several subspecialties, such as interventional nephrology, obstetric nephrology, and the ideal-utopic one is based upon prevention, and early care of common diseases. Each model has strength and weakness, which are commented to enhance discussion on the crucial issue of the philosophy of care behind its practical organization. Increased reflection and research on models of nephrology care is urgently needed if we wish to rise to the challenge of providing earlier and better care for older and more complex kidney patients with acute and chronic kidney diseases, with reduced budgets.

Mortality in Elderly Waiting-List Patients Versus Age-Matched Kidney Transplant Recipients: Where is the Risk?

The number of elderly patients on the waiting list (WL) for kidney transplantation (KT) has risen significantly in recent years. Because KT offers a better survival than dialysis therapy, even in the elderly, candidates for KT should be selected carefully, particularly in older waitlisted patients. Identification of risk factors for death in WL patients and prediction of both perioperative risk and long-term post-transplant mortality are crucial for the proper allocation of organs and the clinical management of these patients in order to decrease mortality, both while on the WL and after KT. In this review, we examine the clinical results in studies concerning: a) risk factors for mortality in WL patients and KT recipients; 2) the benefits and risks of performing KT in the elderly, comparing survival between patients on the WL and KT recipients; and 3) clinical tools that should be used to assess the perioperative risk of mortality and predict long-term post-transplant survival. The acknowledgment of these concerns could contribute to better management of high-risk patients and prophylactic interventions to prolong survival in this particular population, provided a higher mortality is assumed.

Relationship between history of coronary heart disease at dialysis initiation and onset of events associated with heart disease: a propensity-matched analysis of a prospective cohort study

Background

Chronic kidney disease (CKD) is an independent risk factor for cardiovascular disease (CVD) events, and a number of reports have shown a relationship between CKD and CVD in pre-dialysis or maintenance dialysis patients. However, few studies have reported serial observations during dialysis initiation and maintenance. Therefore, we examined whether the incidence of heart disease events differed between CKD patients with and without a history of coronary heart disease (CHD) at dialysis initiation.

Methods

The subjects were patients in the 17 centers participating in the Aichi Cohort Study of Prognosis in Patients Newly Initiated into Dialysis (AICOPP) from October 2011 to September 2013. We excluded nine patients whose outcomes were unknown, as determined by a survey conducted at the end of March 2015. Thus, we enrolled 1,515 subjects into the study. We classified patients into 2 groups according to the history of CHD (i.e., a CHD group and a non-CHD group). Propensity scores (PS) represented the probability of being assigned to a group with or without a history of CHD. Onset of heart disease events and associated mortality and all-cause mortality were compared in PS-matched patients by using the log-rank test for Kaplan-Meier curves. Factors contributing to heart disease events were examined using stepwise multivariate Cox proportional hazards analysis.

Results

There were 254 patients in each group after PS-matching. During observation, heart disease events occurred in 85 patients (33.5%) in the CHD group and 48 (18.9%) patients in the non-CHD group. The incidence was significantly higher in the CHD group (p < 0.0001). The CHD group was associated with higher incidence of heart disease events (vs. the non-CHD group, hazard ratio = 1.750, 95% confidence interval = 1.160–2.639). In addition, comorbidities such as diabetes mellitus, low body mass index, and low serum high-density lipoprotein cholesterol were associated with higher incidence of events.

Conclusion

History of CHD at dialysis initiation was associated with a higher incidence of heart disease events and mortality and all-cause mortality.

Trial registration

UMIN 000007096. Registered 18 January 2012.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-017-0495-8) contains supplementary material, which is available to authorized users.